Fig. 2 Comparison of transistor characteristics between spiro-OMeTAD single crystals and thin films. (A) Transfer characteristics in the saturated regime for the single-crystal FET. (B) Output curve of the single-crystal FET. (C) Transfer characteristics in the saturated regime for the thin-film FET. (D) Output curve of the thin-film FET.
Fig. 3 Modeling of intermolecular charge transport. (A) DFT-ωB97X-D/6-31G** energies and wave functions for the HOMO (left) and HOMO-1 (right) levels of a molecular trimer extracted from the spiro-OMeTAD single crystal along the a direction. Lower panels: Illustration of the transfer integrals estimated for adjacent molecules in the trimer; the blue squares highlight the fluorene rings for which wave-function overlap has a major contribution to intermolecular electronic couplings (transfer integrals). (B) DFT-B3LYP/6-31G** valence band structure and density of electronic states (DOS) of the spiro-OMeTAD single crystal; the crystallographic coordinates of high-symmetry points in the first Brillouin zone correspond to Γ = (0,0,0), X = (0.5,0,0), Y = (0,0.5,0), Z = (0,0,0.5), M = (0.5,0.5,0), and R = (0.5,0.5,0.5).
- Table 1 Key lattice parameters of the spiro-OMeTAD single crystal.
Space group Cell length (Å) Cell angle (°) a b c α β γ Triclinic P−1 (no. 2) 13.66 14.72 17.28 86.23 68.98 80.01
Supplementary Materials
Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/2/4/e1501491/DC1
Single-crystal data file.
fig. S1. Optical microscope image of the spiro-OMeTAD single-crystal FET device.
fig. S2. Optical microscope image of the spiro-OMeTAD thin-film FET device.
fig. S3. Transfer characteristic of lithium salt–doped spiro-OMeTAD thin films.
fig. S4. Transfer characteristics of oxidized spiro-OMeTAD single crystals.
Additional Files
Supplementary Materials
This PDF file includes:
- fig. S1. Optical microscope image of the spiro-OMeTAD single-crystal FET device.
- fig. S2. Optical microscope image of the spiro-OMeTAD thin-film FET device.
- fig. S3. Transfer characteristic of lithium salt–doped spiro-OMeTAD thin films.
- fig. S4. Transfer characteristics of oxidized spiro-OMeTAD single crystals.
Other Supplementary Material for this manuscript includes the following:
Files in this Data Supplement:
- fig. S1. Optical microscope image of the spiro-OMeTAD single-crystal FET device.
